A symposium of the Royal Society of Canada was held in June 1962 to outline what is being done in Canadian oceanography to map salinity, temperature, and plankton in the waters around Canada and in the North Atlantic across to Europe. This volume, based on the symposium, emphasizes the interdisciplinary nature of research in marine biogeography and in the distribution of environmental factors in the sea. The book is intended to show the breadth of biogeographic work in the sea, and the relation between biogeography and the physics and chemistry of the marine environment. It serves also to introduce to the scientific public the new Serial Atlas of the Marine Environment, a scientific journal of a new kind of sponsored jointly by the Royal Society of Canada and the U.S. National Academy of Sciences.